This invention relates to a novel load-supporting plank system that is particularly adapted for being rapidly deployed for the stream egress and bridge access/egress of military vehicles wherein improved means are provided for joining the individual planks to each other in a manner that water and mud penetration at the joints is effectively prohibited. The invention comprises a system of a plurality of planks joined together in an articulable fashion by flexible hinge members in such a way that the system may be folded in accordion or fan fashion that permits efficient packing in a container for transport and for rapid deployment. In one embodiment of the invention the planks are hollow extrusions of aluminum alloy fitted with end plugs, thereby permitting the system to be floatable. However, the plugs are easily removed, and the system, or a portion of the system if desired, becomes sinkable. The planks are folded in accordion fashion and packed in a pallet which preferably is constructed of closed tubular members, and therefore also floatable in water. The pallet is designed to be suspended in front of a deployment vehicle, and the planks are so deployed that the vehicle rides upon the surface of the plank members of the system as the planks are withdrawn from the pallet. Further, the palletized planks may be deployed by other means, such as being manually levered from the pallet while the pallet is resting on the stream shore, and the surfacing will then float away from the pallet. Further embodiments of the invention include planks having a honeycomb core structure and also planks which utilize foam plastic instead of extrusions of aluminum. These embodiments are not sinkable.
The prior art discloses various transportable roadway systems used for military assault purposes in order that the vehicles may traverse soft, swampy, or sandy ground. Paradigms of these are disclosed in Payne U.S. Pat. No. 2,384,395, Abell U.S. Pat. No. 4,277,201, German patent application, Offenlegenschrift No. 2,658,900, and the technical report distributed by Defense Technical Information Center entitled "Assault Trackway Systems Activ Project No. ACL 28/681", Feb. 13, 1969.
The Payne patent discloses a vehicle which is modified to lay wire mesh mats to be used as a landing field, beach apron, temporary road or the like. The Abell patent discloses a transportable roadway system which is loaded on a transport vehicle by folding the roadway layer upon layer and is comprised of a plurality of sections, each section including a plurality of planks positioned edge to edge and bonded by a flexible membrane or fabric, and the adjoining sections are connected by hinges connecting the end planks of each section. The roadway system can be deployed from either the rear of the transporter vehicle or over the front of the vehicle. Offenlegenschrift No. 2,658,900 also discloses a roadway system wherein the planks can be deployed from the rear of the transporting vehicle or over the front of the transporting vehicle. The planks in this case are folded accordion-fashion for transport. The report distributed by Defense Technical Information Center discloses roadway systems that were experimental with in Viet Nam. Two trackway systems are described, one of aluminum extrusions and the other of plastic. In the case of the aluminum trackway, the trackway was dispensed from a spool upon which it was wound, the spool being mounted upon a truck. The trackway is dispensed by rolling it forward over the cab of the truck and under the front and rear wheels. In the case of the plastic trackway, the trackway was dispensed from a reel mounted on the front bumper of a vehicle.
In each of the aforementioned prior art roadway systems there are deficiencies, and there would be serious difficulties in deploying these in an assault egress and bridge access/egress system.